. >> there are over $7 trillion worth of economic events that are going to hit america in the gut. i think impact would be really strong. if anybody thinks this is going to be a slope better wake up. >> ifill: the link between brain injury and sports, new evidence ties repeated blows to the head to long-term damage. we take a look. >> brown: ray suarez looks at the firestorm over israel's announcement it will expand settlements in the west bank. >> ifill: elizabeth brackett looks at how one chicago school is dealing with the transition to new state-wide standards. >> i really did find that the kids do understand more, and they learn more. they're more interested in what they're learning. >> brown: plus, as global carbon dioxide levels hit record highs, we analyze the increasing difficulty of combating climate change, with carol davenport of the "national journal." >> ifill: that's all ahead on tonight's newshour. major funding for the pbs newshour has been provided by: moving our economy for 160 years. bnsf, the engine that connects us. and by the alfred p. sloan foundation. suppor